Not long ago, Hasse Walum, a handsome post-graduate at the Karolinska Institute in Sweden, decided to study the association between a particular gene for what is called a vasopressin receptor and relationship stability. He analyzed the responses of over 550 twins and their partners to questions, some of them intrusive, about their relationships: How often do you kiss your mate? “Have you ever regretted getting married/moving in?” “Have you discussed a divorce or separation with a close friend?” “Rate your degree of happiness in your relationship on a scale of 1-7.”

Walum then sampled the men’s DNA. Getting DNA from the men was simple. You don’t need blood to have access to another person’s genome, just saliva, which the men submitted in a mouth swab.

What Walum discovered was stunning. Focusing on one particular vasopressin receptor gene variant, allele 334, he found that the more copies of it a man had, the weaker his bond with his partner. Men who lacked the gene variant were generally happiest in their relationships — only 15 percent of them had a crisis. Men with one copy were slightly more likely to have marital problems. And men with two copies were, on average, twice as likely to have had a relationship crisis in the past year than men who didn’t have the variant — meaning that 34 percent of them, or one in three, were headed toward a break up. Their partners agreed. Women whose partners carried one or two copies of the allele 334 variant were generally less satisfied with their men, probably because they generally scored as less affectionate than other guys.

Walum also found that men with two copies of the variant were nearly twice as likely not to marry their partners and mothers of their children as men who had no copies of the variant. This suggests that there is something slightly different about the vasopressin receptors in the brains of men who struggle in their roles as partners and fathers. These men may have more difficulty bonding with other people, including their wives and kids.

I imagine that some of you are now scheming to get an allele 334 test for your man. Of the more than five hundred women who responded to my online poll on this topic, nearly 65 percent said they would test their man if given the option.

Ladies, there’s a caveat here, of course. Even if there’s a correlation between this particular gene variant and a man’s behavior, it doesn’t account for all men. Just as the “god gene” and “gay gene” are met with skepticism in the scientific community, so is the “cheating gene.” Even within Walum’s study, there were men with two allele 334 variants who were happy husbands and fathers, and there were men without the variant who were miserable in their relationships. The statistics apply to populations, not individuals, who are also influenced by a other factors — parental role models, partner choice, opportunity to cheat, past loves, age, life satisfaction, religion, hormone levels, and so on.

A two-allele man may become a number one husband under the right circumstances.

As described in BLONDES, the prevailing theory on why the human penis has a distinctive head and corona (rounded projecting border) is that it can scoop out semen deposited in the vagina by a woman’s previous lovers, thus averting a pregnancy. This means the last lover, not the first, gets the head-start.

Not likely, says Dr. Edwin Bowman, in his letter to the editor.

Instead of scooping out other men’s semen, writes Bowman, the penile head and corona scoop out vaginal secretions. After collected, these fluids are then absorbed by the foreskin. The mucous membrane of the foreskin, it turns out, is like a sponge for the stuff.

Why would evolution select for men to absorb vaginal secretions?

Just as semen has “mind control properties,” so do vaginal fluids. When ovulating and most likely to conceive, these secretions contain neurohormones such as pitocin and vasopressin. The latter in particular has been associated with bonding and is thought to trigger protective behavior among males for their partners. Vasopressin, after all, is thought of as a male “love drug.” Flooded with bonding hormones, a guy may be more likely to stick around if he impregnates his partner.

Several times in the last week, twice on the subway and once in a cafe, I sat near a baby-talking couple spweaking wike dis, in a wery squeaky voice, saying wuv wu oochy-coochie poopy. They were all adults in their mid-twenties to mid-forties. They wore leather jackets, high heels, makeup, suits-and-ties. But they acted as if they were in diapers.

I think terms of endearment — Cupcake, Honey, Tootie, Mochi — are sweet. It’s the bwack-and-forth bwabble that bwothers me a bwit, only because I don’t understand the appeal. Of all forms of role play, infantilizing a boyfriend or husband — talking to him as a little girl would a baby doll — just doesn’t seem romantic or arousing.

Yet psychologists consider lovers’ babytalk a real and valid form of bonding. A study by Meredith Bombar and Lawrence Littig suggests it’s a good sign: Babytalkers were more secure and less avoidant in romantic relationships. In effect they’re reactivating primal circuits of attachment. Ickle-bitty-peshus-wuvy cooing reinforces intimacy, tapping into the unconditional love of a parent for child. The old “play” circuits are also activated; as in any form of fantasy, babytalk allows a couple to step outside the limits of self, space, and time. Stress is reduced — the same reason why a recent study on light S&M found that couples who spank together stay together. Babytalking lovers get a blast of dopamine and oxytocin in areas of the brain involved in reward and bonding — the ventral tegmental area, orbitofrontal cortex, and anterior cingulate cortex.

According to psychologists, mutual use of high-pitched voices, soothing whispers, cooing, lisping, and overexpressive faces is a way of “looping” or “mirroring” affection. Exclusive and intimate, it’s an act of trust-building. Think of it as verbal swaddling. Along with the other bonding benefits, babytalk may be a way of flaunting one’s healthy emotional neural circuitry — suggesting not only love and commitment but also strong parental instincts. (Take it to an extreme and more interesting interpretations may be made.)

Psychologists, then, don’t seem troubled by babytalk between lovers. In moderation it’s considered a healthy indulgence. Even so, it’s not my idea of pampering.

Take Our PollIs this the end of love as we know it — exasperating, unpredictable, uncontrollable, and full of rogue potential? Does the future offer sex without emotional mayhem? Fuss-free breakups?

“Love is dead.” “Anti-love drug may be ticket to bliss.” Such are today’s headlines trumpeting the research of neuroscientist Larry Young. Dr Young and his team at Yerkes Research Center are best known for their studies on the love lives of more-or-less monogamous prairie voles. (In BLONDES I describe their fascinating views on the genetic and hormonal basis of bonding and what it might mean for humans. On a related topic, check out my cheating gene post.) The first question inspired by this research is “Can a drug make you fall in love?” The flip side of this coin is just as rich: “Can a drug prevent you from falling in love?”

For now it’s all speculation, but many researchers, including Dr Young, believe the latter is possible. (Fewer care to speculate on the former. Given how difficult love is to define, it’s easier to say you can prevent it than invoke it.) The gist of the idea is that a drug could short-circuit the biochemical pathways that flood the “emotional bonding regions” of the brain with neurohormones such as oxytocin and vasopressin. Just as morning-after pills work by preventing fertilized eggs from implanting, so the “anti-love drug” — oxytocin or vasopressin blockers — would prevent emotional seeds from taking root. Female voles who are given anti-love drugs can mate with a male dozens of times and fail to exhibit any of their usual bonding tendencies, no matter how affectionate the males.

What good is an anti-love drug? The possibilities abound. A few nasal puffs and a woman may more easily have “sex like a man,” feeling pleasure but free of the morning-after anxiety of whether he’s “all that into her.” People in addictive, abusive relationships could just pick up and carry on. Couples may have open marriages without emotional messiness. There may be fewer midlife crises involving trophy wives and umbrella boys. Sex would be only sex. The anti-love drug could be a temporary fix of sanity.

But would you dare take it — even on a short-term basis? At risk of throwing the poll above, my vote is no. What sort of human beings would we be without a range and depth of emotional experience? The angst and anguish of lost love. The self-mending. Even the melancholic savor. What would we learn about ourselves without it? Even in the twenty-first century I’d say it’s better to love and lose than never to love at all.

Imagine there’s a genetic test that could reveal your man’s chances of being a cheater — or, at least, a difficult long-term companion. Would you make him take it? Turns out we’re one step closer to having the option.

Can your genes make you cheat? is one question posed in BLONDES. To answer, I mention recent studies on the monogamous prairie vole and the role of vasopressin, a hormone associated with monogamy. Prairie voles are much more monogamous than their cousins, the montane vole, and the difference might boil down to different variants of vasopressin receptor genes in the two species. (Vasopressin receptors exist in regions of the brain related to trust, reward, and bonding, including the ventral tegmental area or VTA.) Scientists have since speculated that men, too, might vary in their vasopressin receptor genes….and that might make all the difference between faithful guys and cheating rats.

Now there’s more concrete evidence that men do indeed differ in their vasopressin receptor genes, and that that a single genetic variation affects their love lives. Hasse Wallum , a medical epidemiologist at the Karolinska Institute, found that men who had one or two copies of allele RS3 334, a variant of a vasopressin receptor gene, were more likely to have relationship crises than men who lacked the variant. The wives of guys with the variant cited more relationship problems than did women married to men without the variant. Interestingly, studies have also found that autistic men are more likely to have copies of this wayward gene variant.

Although the study stresses that men with RS3 334 alleles aren’t guaranteed to be romantic duds and deadends — after all, the effects are modest, other genes may be involved, and cultural factors have their sway — but it inspires the imagination. What do you do if your man has the “cheating” gene, putting your relationship at greater risk of strife and infidelity? Do you still date him – or do you dump him? Would you even want to know?